From 508217604edc5f098783b2b9513ffdec321d9b07 Mon Sep 17 00:00:00 2001
From: zaniebot <242828183+zaniebot@users.noreply.github.com>
Date: Wed, 21 Oct 2026 18:19:30 +0000
Subject: [PATCH 1/2] Keep the perf trampoline end marker inside its text
 section

---
 .../Build/2026-10-21-18-00-00.gh-issue-0.perf-trampoline.rst    | 2 ++
 Python/asm_trampoline_aarch64.S                                 | 1 +
 Python/asm_trampoline_riscv64.S                                 | 1 +
 Python/asm_trampoline_x86_64.S                                  | 1 +
 4 files changed, 5 insertions(+)
 create mode 100644 Misc/NEWS.d/next/Build/2026-10-21-18-00-00.gh-issue-0.perf-trampoline.rst

diff --git a/Misc/NEWS.d/next/Build/2026-10-21-18-00-00.gh-issue-0.perf-trampoline.rst b/Misc/NEWS.d/next/Build/2026-10-21-18-00-00.gh-issue-0.perf-trampoline.rst
new file mode 100644
index 00000000000000..f5b066d31ec71c
--- /dev/null
+++ b/Misc/NEWS.d/next/Build/2026-10-21-18-00-00.gh-issue-0.perf-trampoline.rst
@@ -0,0 +1,2 @@
+Add a byte after the ELF perf trampoline end marker so it does not share
+the following function's address, which BOLT may otherwise move.
diff --git a/Python/asm_trampoline_aarch64.S b/Python/asm_trampoline_aarch64.S
index b3aeb728de200c..aef34014ae8552 100644
--- a/Python/asm_trampoline_aarch64.S
+++ b/Python/asm_trampoline_aarch64.S
@@ -57,6 +57,7 @@ __Py_trampoline_func_end:
 #else
     .globl	_Py_trampoline_func_end
 _Py_trampoline_func_end:
+    .byte 0
     .section        .note.GNU-stack,"",@progbits
 #endif
 
diff --git a/Python/asm_trampoline_riscv64.S b/Python/asm_trampoline_riscv64.S
index 6125ba95373f95..21aafbcf23d6f0 100644
--- a/Python/asm_trampoline_riscv64.S
+++ b/Python/asm_trampoline_riscv64.S
@@ -9,4 +9,5 @@ _Py_trampoline_func_start:
     jr      ra
     .globl	_Py_trampoline_func_end
 _Py_trampoline_func_end:
+    .byte 0
     .section        .note.GNU-stack,"",@progbits
diff --git a/Python/asm_trampoline_x86_64.S b/Python/asm_trampoline_x86_64.S
index 0e6b11589eafc8..e1a714413abfd4 100644
--- a/Python/asm_trampoline_x86_64.S
+++ b/Python/asm_trampoline_x86_64.S
@@ -21,6 +21,7 @@ __Py_trampoline_func_end:
 #else
     .globl	_Py_trampoline_func_end
 _Py_trampoline_func_end:
+    .byte 0
     .section        .note.GNU-stack,"",@progbits
 #endif
 # Note for indicating the assembly code supports CET

From 36ee3ab4f34ea5590df87a74ac0db30416b2d575 Mon Sep 17 00:00:00 2001
From: zaniebot <242828183+zaniebot@users.noreply.github.com>
Date: Wed, 21 Oct 2026 19:07:11 +0000
Subject: [PATCH 2/2] Link `NEWS` entry to the upstream issue

---
 ...st => 2026-10-21-18-00-00.gh-issue-128883.perf-trampoline.rst} | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 rename Misc/NEWS.d/next/Build/{2026-10-21-18-00-00.gh-issue-0.perf-trampoline.rst => 2026-10-21-18-00-00.gh-issue-128883.perf-trampoline.rst} (100%)

diff --git a/Misc/NEWS.d/next/Build/2026-10-21-18-00-00.gh-issue-0.perf-trampoline.rst b/Misc/NEWS.d/next/Build/2026-10-21-18-00-00.gh-issue-128883.perf-trampoline.rst
similarity index 100%
rename from Misc/NEWS.d/next/Build/2026-10-21-18-00-00.gh-issue-0.perf-trampoline.rst
rename to Misc/NEWS.d/next/Build/2026-10-21-18-00-00.gh-issue-128883.perf-trampoline.rst